1. Field of the Invention
The present invention relates to a microphone and a manufacturing method thereof.
2. Description of the Related Art
Microphones, which convert a sound wave into an electrical signal, are currently are being manufactured in a decreased size using Micro Electro Mechanical System (MEMS) technology. The MEMS microphone is more resistant to humidity and heat than an Electret Condenser Microphone (ECM), which allows integration with a signal processing circuit.
In general, the MEMS microphone is divided into a capacitive type and a piezoelectric type. The capacitive type of MEMS microphone includes a fixed electrode and a vibration film, so when sound pressure is applied to the vibration film from the exterior, a capacitance value is changed while an interval between the fixed electrode and the vibration film is also changed. The sound pressure is measured using a generated electrical signal. The piezoelectric type of MEMS microphone includes a vibration film. In addition, when the vibration film is changed by sound pressure from the exterior, an electrical signal is generated by a piezoelectric effect, to measure the sound pressure.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.